Batchupdates not working as expected


HI There

Just started playing with batch updates in ADO, have set up a TADODataset with clUseClient, ltBatchoptimistic, ctKeyset an appropriate connection and SQL statement. The dataset opens up OK
but when I attempt to change a value I get 'dataset not in edit of insert mode'

None of the examples seem to indicate placing the dataset into 'edit' mode, however if I do this by 'myDS.edit' it all works any suggestions ????
.